On Thu, Oct 03, 2019 at 11:50:39PM -0700, Eric Biggers wrote: > From: Eric Biggers <ebiggers@xxxxxxxxxx> > > Kmemleak is falsely reporting a leak of the slab allocation in > sctp_stream_init_ext(): > > BUG: memory leak > unreferenced object 0xffff8881114f5d80 (size 96): > comm "syz-executor934", pid 7160, jiffies 4294993058 (age 31.950s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<00000000ce7a1326>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] > [<00000000ce7a1326>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<00000000ce7a1326>] slab_alloc mm/slab.c:3326 [inline] > [<00000000ce7a1326>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 > [<000000007abb7ac9>] kmalloc include/linux/slab.h:547 [inline] > [<000000007abb7ac9>] kzalloc include/linux/slab.h:742 [inline] > [<000000007abb7ac9>] sctp_stream_init_ext+0x2b/0xa0 net/sctp/stream.c:157 > [<0000000048ecb9c1>] sctp_sendmsg_to_asoc+0x946/0xa00 net/sctp/socket.c:1882 > [<000000004483ca2b>] sctp_sendmsg+0x2a8/0x990 net/sctp/socket.c:2102 > [...] > > But it's freed later. Kmemleak misses the allocation because its > pointer is stored in the generic radix tree sctp_stream::out, and the > generic radix tree uses raw pages which aren't tracked by kmemleak. > > Fix this by adding the kmemleak hooks to the generic radix tree code. > > Reported-by: syzbot+7f3b6b106be8dcdcdeec@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
